diff --git a/.changeset/loud-log-fields.md b/.changeset/loud-log-fields.md
new file mode 100644
index 0000000..d03be05
--- /dev/null
+++ b/.changeset/loud-log-fields.md
@@ -0,0 +1,5 @@
+---
+"helm-charts": patch
+---
+
+feat: set `severityNumberExpression: "SeverityNumber"` and `eventNameExpression: "EventName"` on the default Logs source (only applies to new installs; existing sources are not modified)
diff --git a/charts/clickstack/tests/default-env-vars_test.yaml b/charts/clickstack/tests/default-env-vars_test.yaml
index 5a617a4..9d5fdaa 100644
--- a/charts/clickstack/tests/default-env-vars_test.yaml
+++ b/charts/clickstack/tests/default-env-vars_test.yaml
@@ -116,6 +116,15 @@ tests:
           path: spec.template.spec.containers[0].env[?(@.name == "DEFAULT_SOURCES")].value
           pattern: '"kind": "trace",[^}]*"spanLinksValueExpression": "Links"'
 
+  - it: should set severity number and event name on the default log source
+    asserts:
+      - matchRegex:
+          path: spec.template.spec.containers[0].env[?(@.name == "DEFAULT_SOURCES")].value
+          pattern: '"kind": "log",[^}]*"severityNumberExpression": "SeverityNumber"'
+      - matchRegex:
+          path: spec.template.spec.containers[0].env[?(@.name == "DEFAULT_SOURCES")].value
+          pattern: '"kind": "log",[^}]*"eventNameExpression": "EventName"'
+
   # metricTables keys must match MetricsDataType values; unknown keys
   # (e.g. camelCase "exponentialHistogram") are silently dropped by HyperDX.
   - it: should register all OTel metric tables on the default metric source
diff --git a/charts/clickstack/values.yaml b/charts/clickstack/values.yaml
index 991d788..b0bab12 100644
--- a/charts/clickstack/values.yaml
+++ b/charts/clickstack/values.yaml
@@ -232,6 +232,8 @@ hyperdx:
           "resourceAttributesExpression": "ResourceAttributes",
           "defaultTableSelectExpression": "Timestamp,ServiceName,SeverityText,Body",
           "severityTextExpression": "SeverityText",
+          "severityNumberExpression": "SeverityNumber",
+          "eventNameExpression": "EventName",
           "traceIdExpression": "TraceId",
           "spanIdExpression": "SpanId",
           "connection": "Local ClickHouse",